Reactor Inlet Research Articles

Визначення консервативних умов моделі реактивнісної аварії на РБМК‑1000

Analytical studies have been performed on the model of a reactivity accident at the 4th Unit of the Chornobyl NPP with an RBMK-1000-type reactor. The model of the RBMK-1000 reactor was developed based on the equations of nuclear reactor kinetics. In the model, the reactivity changes as a result of external influences (the movement of control rods; changes in the coolant temperature at the reactor inlet), as well as a result of feedback on reactivity effects (changes in fuel temperature, coolant density, 135Xe concentration). The change in the coolant density takes into account the formation of steam in the reactor core, and the coolant pressure is introduced into the model as an external factor, according to the results of the registered data during the accident on 26.04.1986. There is a high sensitivity of the RMBK-1000 reactivity model to the absolute values of reactivity coefficients that have occurred on the eve of the accident (negative reactivity coefficient by fuel temperature, positive steam coefficient of reactivity). Therefore, the study is conducted for different combinations of values of the efficiency of the control rods, reactivity coefficients, as well as other factors affecting the course of the accident — emergency protection triggering time, and reactor power level before the accident. Considering that the main stage of the accident lasted less than 10 s, fuel destruction is possible when the critical value of fuel enthalpy is reached, at which the fuel dispersion process begins. The results of modeling of reactivity accident on RBMK-1000 with the values of parameters of reactivity effects, which best correspond to the chronology of recorded events as well as to the recorded values of technological parameters, are presented.

Investigation of hydration/dehydration processes in a fluidized bed reactor using MgO/Mg(OH)2 thermochemical energy storage system

Thermochemical energy storage (TCES) is a promising energy storage method because of its high energy storage density and long-term storage ability. The reactor is the most critical part of the TCES system, and the fluidized bed reactor (FBR) is a novel reactor, which is not restricted by the low effective thermal conductivity of energy storage materials. However, there is little theoretical guidance about the design and operation of the FBR for a TCES system. In this study, we investigated the performance of an FBR using MgO/Mg(OH)2 as reaction materials by establishing a numerical model followed by experimental validation. The influence of operating parameters on the bed temperature was discussed based on numerical results. According to the sensitivity analysis, the reactor inner diameter, material mass, and inlet gas velocity were the main factors affecting the bed temperature. The optimal boundary surface temperature was analyzed, which influences the proportion of TCES in the total heat storage.

Performance enhancement of methanol reforming reactor through finned surfaces and diffused entry for on-board hydrogen generation

Hydrogen-rich combustion in engines helps in reducing pollutants significantly. But hydrogen usage on a moving vehicle is not getting large-scale user acceptance mainly due to its poor energy storage density resulting in shorter driving ranges. This storage issue led to the hunt for mediums that can efficiently produce on-board hydrogen. Methanol proves to be an efficient alcohol fuel for producing hydrogen through steam reforming reaction. The heat energy required for such endothermic reaction is obtained through exhaust engine waste energy and this process is collectively known as thermochemical recuperation. However, the conventional reactor used for this process faces a lot of problems in terms of efficiency and methanol conversion. In this study, an attempt has been made to improve the design of the reactor for on-board hydrogen generation using engine exhaust heat for addressing the challenges related to performance and hydrogen yield. For enhancing the heat transfer, a finned surface (straight & wavy) was introduced in the reactor which resulted in an increment in methanol conversion significantly. It was found that wavy fin improved the methanol conversion up to 96.8% at an exhaust inlet temperature of 673 K. Also, a diffusing inlet section was introduced to increase the residence time of reactant gases while passing through the catalyst zone. Under given inlet conditions, the methanol conversion for 6° diffuse inlet reactor goes up to 87.9% as compared to 75.4% for the conventional reactor.

Is There a Stable Deacon Catalyst? Computational Screening Approach for the Stability of Oxide Catalysts under Harsh Conditions

Under harsh reaction conditions, lack of catalyst stability can impede the large-scale implementation of a technical process. Current computational screening approaches address catalyst activity or selectivity, but screening models that predict catalyst stability under operating conditions are still lacking. Herein, a screening model is presented that can predict catalyst stability under harsh reaction conditions based on the thermodynamic data of bulk phases while accounting for variations in the operating conditions (temperature, gas feed composition, and conversion). It is applied to oxide catalysts for the oxidation of HCl (Deacon reaction), where catalysts can chlorinate irreversibly or leach from the catalyst bed in the form of volatile chlorides and oxychlorides, resulting in loss of catalyst activity. Two numerical descriptors are computed from the thermodynamic data, ranking the oxides according to their stability against chlorination and vaporization, which enables large-scale screening. The underlying computations provide detailed insights on the possible reactions of the catalyst with the gas stream in the form of reaction free energy diagrams. This allows one to identify where the reactor degradation is the most severe and improve the catalyst stability by addressing these stability bottlenecks. For the Deacon reaction, the oxides and chlorides of 66 elements are examined. The two descriptors are empirically found to be largely complementary, which means that most oxides are prone to either chlorination or volatility, with a few exceptions. It is found that both chlorination and volatility are most severe close to the reactor inlet, which suggests that a highly stable catalyst material must be employed at the reactor inlet. The late rare-earth oxychlorides, as well as Nb2O5 and Ta2O5, are identified as promising candidates with high stability in both categories at the reactor inlet. The developed model can be applied to catalytic processes where phase transformations of the catalyst material under operating conditions are the major cause of catalyst deactivation and are in principle applicable to any process that runs at sufficiently high temperatures.

Effects of removing carbon particles of different size with nonthermal plasma generated by packed-bed dielectric barrier discharge reactor

A self-designed packed-bed dielectric barrier discharge (PB-DBD) reactor was used to explore the effects of carbon particle size distribution, reaction chamber temperature and reactor inlet flow on the removal effect of carbon particles with different particle sizes. The results indicated that in the process of non-thermal plasma (NTP) oxidation of carbon particles, particles with larger particle size are decomposed into new nanoparticles. When the temperature of the reaction chamber increased from 25 to 200 ℃, the number concentration removal efficiency and rate of nanoparticles, ultrafine particles and total particles increased. With the increase of the inlet flow of the reactor, the O3 concentration first increased and then decreased and the number concentration removal rate of nanoparticles, ultrafine particles and total particles showed the same trend as the O3 concentration. At the inlet oxygen flow of 3 L/min, the O3 concentration and carbon particle removal rate were the maximum.

Mechanical stress and strain investigation of sulfonated Poly(ether ether ketone) proton exchange membrane in fuel cells: A numerical study

Mechanical durability of hydrocarbon-based proton exchange membranes in long-term fuel cell operation is vital for their successful commercialization. Herein, a complex finite element model is developed that couples electrochemical performance of sulfonated poly(ether ether ketone) (SPEEK) membrane with its mechanical response at different operating conditions to predict the susceptible sites to mechanical failure. To this end, the impacts of cell voltage (0.1–0.9 V), operating temperature (30–80 °C) and backpressure (0.3–1.5 bar), inlet reactants relative humidity (30–100%), and clamping pressure (1–5 MPa) on hydration and consequently, stress and strain formation in the SPEEK membrane are investigated. Results suggest that SPEEK membrane, particularly at the channel outlet, undergoes the greatest swelling-induced degradation when the cell is running at low voltages, high temperature and backpressure values. Clamping pressure, however, imposes compressive stress and thinning upon the land region and is the dominant factor compared to hygrothermal swelling, albeit high hydration level shifts the maximum stress to the channel region. Despite superior resistance to different hygrothermal conditions and lower chance of thinning under the clamping pressure, Nafion membrane exhibits a relatively higher risk of wrinkle deformation under compression. This study provides insights into the mechanical response of hydrocarbon-based membranes under various fuel cell conditions.

Interface Mass Transfer in Reactive Bubbly Flow: A Rigorous Phase Equilibrium-Based Approach

In this work, the driving force of interfacial mass transfer is modeled as deviation from the gas–liquid equilibrium, which by assumption is thought to exist at the interface separating the gas and liquid phases. The proposed mass transfer model provides a flexible framework where the phase equilibrium description in the driving force can be substituted without difficulties, allowing the mass transfer modeling of distillation, absorption/stripping, extraction, evaporation, and condensation to be based on a thermodynamically consistent phase equilibrium formulation. Phase equilibrium by the Soave–Redlich–Kwong equation of state (SRK-EoS) is in this work compared to the results of the classical Henry’s law approach. The new model formulation can predict mass transfer of the solvent, which Henry’s law cannot. The mass transfer models were evaluated by simulating a single-cell protein process operated in a bubble column bioreactor, and the solubilities computed from the SRK-EoS and Henry’s law were in qualitative agreement, albeit in quantitative disagreement. At the reactor inlet, the solubility of O2 and CH4 was 150% higher with the SRK-EoS than with Henry’s law. Furthermore, the SRK-EoS was computationally more expensive and spent 10% more time than Henry’s law.

Towards thermochemical recuperation applying combined steam reforming and partial oxidation of methane: Thermodynamic and experimental considerations

A novel adaption of the thermochemical recuperation (TCR) approach is presented in this paper. Combined steam reforming and the partial oxidation of methane is applied to a TCR system of an oxy-fuel furnace using natural gas as fuel. In comparison to the chemical reactions currently used for TCR (steam-, bi- and tri-reforming), the presented approach offers two major advantages. First, the reactants are provided without recirculating parts of the exhaust gases, preventing the contamination of reactants by impurities in the exhaust gases. Second, by adding oxygen to the reactants the quantity of water vapour required to achieve the full conversion is reduced and additionally the formation of carbon deposits is avoided.In order to determine the optimum application parameters for the presented system, thermodynamic and experimental investigations were performed. In these investigations, the main operation parameters, the H2O/CH4 and O2/CH4 ratios were varied. These investigations resulted in the following outcomes, which distinguish them from those conducted in previously published studies:(I) The maximum increase in the combustion efficiency was quantified. The thermodynamic considerations resulted in a 16.5% reduction in the fuel and oxidizer consumption when a constant furnace exhaust gas temperature of 1200°C was presumed. (II) CH4 conversion rates of up to 100% were observed in the reforming experiments. (III) Experimental investigations on the influence of the addition of O2 and H2O on the formation of carbon deposits resulted in coke-free operation when a molar ratio of CH4/H2O/O2 = 1/1/0.3 was applied at the reactor inlet.

3D printed microfluidic mixer for real-time monitoring of organic reactions by direct infusion mass spectrometry

3D printing is a technology that has revolutionized traditional rapid prototyping methods due to its ability to build microscale structures with customized geometries in a simple, fast, and low-cost way. In this sense, this article describes the development of a microfluidic mixing device to monitor chemical reactions by mass spectrometry (MS). Microfluidic mixers were designed containing 3D serpentine and Y-shaped microchannels, both with a pointed end for facilitating the spray formation. The devices were fabricated entirely by 3D printing with fusion deposition modeling (FDM) technology. As proof-of-concept, micromixers were evaluated through monitoring the Katritzky reaction by injecting simultaneously 2,4,6-triphenylpropyllium (TPP) and amino acid (glycine or alanine) solutions, each through a different reactor inlet. Reaction product was monitored online by MS at different flow rates. Mass spectra showed that the relative abundances of the products obtained with the device containing the 3D serpentine channel were three times greater than those obtained with the Y-channel device due to the turbulence generated by the barriers created inside microchannels. In addition, when compared to the conventional electrospray ionization mass spectrometry (ESI-MS) technique, the 3D serpentine mixer offered better performance measured in relation to the relative abundance values for the reaction products. These results as well as the instrumental simplicity indicate that 3D printed microfluidic mixer is a promising tool for monitoring organic reactions via MS.

Heat and mass transfer in a metal hydride reactor: combining experiments and mathematical modelling

Heat transfer in porous metal hydride (MH) beds determines efficiency of MH devices. We present a COMSOL Multiphysics numerical model and experimental investigation of heat and mass transfer in a MH reactor filled with 4.69 kg of AB5 type alloy (Mm0.8La0.2Ni4.1Fe0.8Al0.1). To achieve an agreement between the model and experiments it is necessary to include a flow control device (inlet valve or flow regulator) into the model. We propose a simplified and easy-to-calculate boundary condition based on a porous domain with variable permeability at reactor inlet. The permeability of the domain is connected with hydrogen mass flow by a PID controller. Thus, boundary conditions for the inlet pressure and mass flow are coupled and heat transfer inside the reactor could be calculated without additional assumptions applied to heat and mass transfer in the MH bed.

Scale-up of high-pressure F-T synthesis in 3D printed stainless steel microchannel microreactors: Experiments and modeling

Scale-up of Fischer-Tropsch (F-T) synthesis using microreactors is very important for a paradigm shift in the production of fuels and chemicals. The scalability of microreactors for F-T Synthesis was experimentally evaluated using 3D printed stainless steel microreactors, containing seven microchannels of dimensions 1000 µm × 1000 µm × 5cms. Mesoporous silica (KIT-6), with high surface area, containing ordered mesoporous structure was used to incorporate 10% cobalt and 5% ruthenium using a one-pot hydrothermal method. Bimetallic Co-Ru-KIT-6 catalyst was used for scale-up of F-T Synthesis. The performance of the catalysts was evaluated and examined for three different scale-up configurations (stand-alone, two, and four microreactors assembled in parallel) at both atmospheric pressure and 20 bar at F-T operating temperature of 240 °C using a syngas molar ratio (H2:CO) of 2. All three configurations of microreactors yielded not only comparable CO conversion (85.6–88.4%) and methane selectivity (~14%) but also similar selectivity towards lower gaseous hydrocarbons like ethane, propane, and butane (6.23–9.4%) observed in atmospheric F-T Synthesis. The overall selectivity to higher hydrocarbons, C5 + is in the range of 75–82% at 20 bars.A CFD model was used to investigate the effect of different design features and numbering up approaches on the performance of the microchannel reactor. The effect of the reactor inlet, the mixing internals and the channel designs on the dead zone %, the quality index factor, the cooling requirement and the maximum dimensionless temperature within the microreactor were quantified. There is no significant effect of increasing the channel width on the microreactor performance and operation of the microchannel reactor at lower Nusselt number that results in higher CO conversion. Increasing the channel width reduced the maximum temperature exhibited in the channel. Finally, the effect of increasing the y/x stacking ratio, i.e. having more reactor units in parallel compared to series, was investigated. Increasing the y/x ratio increased the cooling requirement and the maximum dimensionless temperature increase within the unit decreased the productivity. To minimize the productivity losses, numbering up in series is the better approach; however further analysis must be done to delineate heat removal requirements.

A numerical study on methanol steam reforming reactor utilizing engine exhaust heat for hydrogen generation

Internal combustion engines are used in most vehicles around the world to power the transport sector. Efficiency improvement, emission reduction, and utilization of alternative fuels are the main aspects of current IC engine research. Hydrogen-enhanced combustion proved to be one of the efficient ways to achieve such goals. But the problem lies in the storage of hydrogen for the transportation sector, and on-board fuel reforming is a promising option for solving this issue. It deals with transforming a suitable liquid fuel (methanol) into an H2-rich gas using a catalytic conversion process. For sustaining the reforming reaction, the required heat energy is taken from engine exhaust waste heat, this process is known as thermochemical recuperation. Number of studies on the reformers utilized for on-board hydrogen generation using engine exhaust heat are limited in the literature. The present study investigates the performance of a reactor that uses the exhaust gas heat energy for sustaining the reforming reaction. A numerical analysis was performed over a selected reactor where exhaust gases were flowing at one side, while on the other, the reforming reaction was taking place with the help of heat provided by high-temperature exhaust gases. A packed bed-type reactor was chosen for the current study and a parametric study was conducted where the effects of various operating parameters on both reacting and heating sides on the reactor's performance were investigated. It was found that temperature was the most influential inlet parameter among others. Steam/Carbon ratio and flow configuration had a negligible effect on the hydrogen yield as well as methanol conversion. Reactant inlet velocity increment revealed a significant drop in methanol conversion as it reduces the residence time for reforming reaction in the catalyst zone.

Thermodynamic analysis and optimization of the combined supercritical carbon dioxide Brayton cycle and organic Rankine cycle‐based nuclear hydrogen production system

The Supercritical Carbon Dioxide Brayton Cycle (SCBC) with high efficiency is a very promising thermodynamic cycle to replace the Steam Rankine Cycle (SRC) as the power cycle of a Nuclear Hydrogen Production (NHP) system. However, detailed research on the NHP system using SCBC as a power cycle has not been carried out so far and the system's thermodynamic characteristics are not well known. To fill this research gap, three promising very high-temperature gas-cooled reactor and copper-chlorine cycle-based NHP systems using different power cycles including SRC, SCBC, and combined SCBC and Organic Rankine Cycle (ORC) are proposed and studied in this work. The energy and exergy analysis method and the particle-swarm optimization algorithm have been used respectively to model and optimize the system. In addition, a parametric analysis based on two typical reactor concepts has been performed to comprehensively investigate the system's thermodynamic characteristics. Finally, a performance comparison of three systems under different hydrogen production loads has been conducted. Major results show that under different hydrogen production loads, the variations in the thermodynamic performance of the SCBC-based NHP system are sensitive to the reactor inlet temperature. Under low reactor inlet temperatures (≤587°C), the thermal efficiency of the SCBC is less than 37%. Besides, increasing the compressor pressure ratio of SCBC can enhance the system's thermodynamic performance, and the system's thermal and exergy efficiencies are improved by about 0.7% to 3.7% and 1.0% to 5.3% respectively by using ORC. Highlights Three VHTR and Cu-Cl cycle-based nuclear hydrogen production systems are studied. Three systems are modeled based on the energy and exergy analysis method. Parametric analysis and optimization under two reactor concepts are conducted. SCBC's thermal efficiency under low reactor inlet temperatures is less than 37%. System overall thermal efficiency is improved by about 0.7% to 3.7% through using ORC.

Synergies in renewable fuels and exhaust heat thermochemical recovery in low carbon vehicles

The impact of renewable fuels on exhaust energy recovery using catalytic thermochemical process in modern gasoline direct injection is studied with main aim of reducing vehicle carbon footprints. It is proven that supplying the engine with increased calorific value reformate would be beneficial in terms of CO2 reduction and fuel economy. In this research, the influence of butanol and ethanol on heat recovery, H2 production, and reforming efficiency are analytically and experimentally studied under various key parameters, including steam to carbon molar ratio and reactor inlet temperature under lean engine operating condition. Gibbs free energy and chemical equilibrium analyses are implemented to identify the key reaction pathways in reforming of the fuels. At lower exhaust gas temperatures where the reactions are thermodynamically limited the conversion rate is mainly controlled by the steam to carbon molar ratio and reducing fuel flow rate leads to a significant increase in fuel conversion levels. Maximum calorific value was achieved by ethanol reforming at 600 °C. However, at higher temperatures and steam to carbon molar ratios, butanol generally indicates better performance in terms of engine fuel economy, energy replacement by reformate, and CO2 reduction. These advantages are attributed to higher calorific value and higher reforming process efficiency of butanol compared to ethanol. In contrast, at lower temperatures, ethanol reforming generates more H2 as a result of highly endothermic nature of butanol steam and dry reforming reactions compared to ethanol with weaker molecular bonds and higher molecular diffusivity rate which leads to efficient use of the catalyst.

Derivative‐Free Optimization of a Fixed‐Bed Methanol Synthesis Reactor

AbstractA one‐dimensional heterogeneous fixed‐bed methanol synthesis reactor model was developed for the optimization of carbon conversion and rate of methanol production. The developed model was validated both at pellet and reactor scales. The reactor inlet syngas composition and cooling water temperature, i.e., the design variables, providing the highest carbon conversion and rate of methanol production were determined by a constrained derivative‐free optimization algorithm. The results revealed that after optimization the carbon conversion was increased by 12 % and the rate of methanol production by 48 %. Under the optimized conditions, the stoichiometric number was in the range of industrial values.

Analysis and estimation of gas-liquid flow pattern in packed bed compact tubular reactors

One of the factors that influence the performance of packed bed reactors is the flow pattern, and many flow pattern maps have been reported so far. In this study, a gas-liquid flow pattern map of a packed bed compact reactor, which is being increasingly used in the flow synthesis of functional chemicals, was constructed, and two types of flow patterns, trickle flow and pulse flow, were identified. In addition, an estimation method was developed to distinguish the trickle flow and pulse flow from differential pressure or voltage when the flow inside the reactor cannot be visually recognized from the outside. The effects of the liquid flow rate and the slug formation frequency at the mixer on the pulsation frequency, which is a parameter in reaction optimization, were examined. As a result, it was shown that the pulsation frequency increases as the liquid flow rate increases under a fixed gas flow rate and that the pulsation frequency and the slug formation frequency do not always match due to the possibility of coalescence of the gas and liquid slugs at the reactor inlet.

Analysis of methanol synthesis using CO2 hydrogenation and syngas produced from biogas-based reforming processes

Utilizing the greenhouse gas CO2 as a feedstock in chemical processing can offer alternative solutions to long-term storage. In this study, a systematic analysis of methanol synthesis performance was analyzed based on both thermodynamic equilibrium and kinetic models using captured CO2 and syngas produced from biogas as feedstock. Using reactor inlet temperature as a parameter, it was found that methanol yield can be enhanced by increasing residential time from increased reactor diameter. The longer reactor can increase the residential time but a large pressure drop caused a decrease in methanol yield. Due to the exothermic reaction nature, methanol yield from an adiabatic reactor is lower than that from the isothermal reactor due to temperature rise. From the results obtained for CO2 hydrogenation, methanol yield can be enhanced by water removal. The CO2 conversion was found to increase with increased reaction temperature due to methanol and carbon monoxide productions. Using CO and CO2 as limiting species, high combined CO and CO2 conversion can be obtained from syngas with low CO2/H2 and high CO/H2 ratios. However, methanol production per mole of H2 depends on the H2 utility instead of combined CO and CO2 conversion. Finally, syngas produced from biogas by using combined dry and steam reforming reactions was used as the feedstock for the methanol synthesis. To obtained the syngas composition suggested from industrial applications, CH4 and H2O were added in the combined reforming process. With higher CH4 content in the biogas, higher methanol production and lower water production can be obtained. With an increased recycle ratio for unreacted syngas, methanol production can be enhanced.

Power-to-gas: CO2 methanation in a catalytic fluidized bed reactor at demonstration scale, experimental results and simulation

CO2 methanation tests were carried out in a demonstration scale fluidized bed reactor (400 kWSNG capacity) to investigate its efficiency and flexibility towards operating conditions fluctuations associated with Power-to-Methane (PtM) production units. A wide range of operating conditions were explored: pressure (2–4 bara), reaction temperature (260−375 °C), H2/CO2 inlet ratio (1.5–4.8), heat released by the reaction exothermicity (13.4–32.7 kWth), and U/Umf (2.2–7.2). Whatever the operating conditions, this technology (reactor and catalyst) reached the maximum possible conversion, i.e. the thermodynamic equilibrium, in only one step. These excellent performances resulted from efficient management of methanation exothermicity (temperature gradient in the fluidized bed is lower than 20 °C) and optimized catalyst activity (even at low temperature: 280 °C). In addition to its high flexibility towards operating conditions, short stabilization time (<30 min) was required for the process to reach permanent and stable regime when the operating condition setpoints were changed. Simulations were performed to investigate different process chains efficiency for producing SNG (Substitute Natural Gas) compliant with natural gas grid standards. A process chain composed of the fluidized bed reactor studied in this article followed by a condensation step, a partial recirculation stream to the reactor inlet, and a polishing reactor was proved to be an interesting solution to produce high quality SNG with reduced equipment and compression cost. The present reactor together with the specific metal-based catalyst developed in this study appear as a very efficient and flexible solution for PtM application.

An operation strategy for mitigating the degradation of solid oxide electrolysis cells for syngas production

Three cells were tested under different conditions to mimic the situation with stacks arranged in gas flow series or parallel. The effects of reactant conversion ratio and inlet gas composition on the cell performance and durability were studied. The cells were operated under −1 A/cm2 at 800 °C for H2O + CO2 co-electrolysis. Flows were adjusted to realize the same overall production of syngas. Detailed electrochemical characterization was performed before, during and after the aging test and microstructural changes after aging were investigated. The results show that a gas-flow series arrangement is advantageous as it leads to reduced cell degradation: Reducing the H2O + CO2 conversion from 56% of a gas flow “parallel” case (Cell P) to 28% in the upstream of the series connected cells (Cell SU) and 39% in the downstream one (Cell SD) reduces the overall cell voltage degradation rate from 372 mV/kh for Cell P to140 mV/kh and 69 mV/kh for Cells SU and SD, respectively. This is tentatively ascribed to the “milder” overall conditions realized in the gas flow series case, where the average as well as maximum polarization (and local current density) is reduced relative to the parallel flow case.

TIME-SERIES MODEL: HYBRID FIRST-PRINCIPLE WITH OPERATIONAL DATA FOR OPTIMISATION OF AN INDUSTRIAL ENDOTHERMIC REACTOR SYSTEM

It is crucial to identify and manage main pain point contributor(s) in the hydrocarbon value chain in maximising revenue and cash generation. Recently, PETRONAS has embarked on the initiative to maximise the production of propane value chain by addressing the run length limitation issue due to increasing coking rate in one endothermic reactor system. Hybrid of the first principle and plant operational data were used and modelled in a time-series manner. Several high impact influential variables were selected and incorporated into the model, i.e. hydrocarbon throughput, hydrogen-to-hydrocarbon ratio, reactor inlet temperature and days-onstream. The hybrid modelling approach is used to find optimum start-of-run operating conditions, control coke formation rate in the presence of variations in operating conditions throughout the run length, and manoeuvre the intermediate operating strategies to achieve the desired run length. The current operation with the implementation of new operating strategies derived from the model shows coke formation reduction up to 70% compared to the historical trending, on-track to achieve the desired run length equivalent to the catalyst expected life, which has never been achieved since in operation. The model can be enhanced in future work to achieve the maximum possible yield throughout the run length and predict the anticipated production with the corresponding operating strategies.